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Why is electrical power required at all when the elevator is descending? Why should there be a limit on the number of passengers in this case? - Physics

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प्रश्न

Why is electrical power required at all when the elevator is descending? Why should there be a limit on the number of passengers in this case?

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उत्तर

When the elevator is descending, then electric power is required to prevent it from falling freely under gravity.

Also, as the weight inside the elevator increases. its speed of descending increases. therefore, there should be a limit on the number of passengers in the elevator to prevent the elevator from descending with large velocity.

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अध्याय 6: Work, Energy and Power - Exercises [पृष्ठ ४५]

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एनसीईआरटी एक्झांप्लर Physics [English] Class 11
अध्याय 6 Work, Energy and Power
Exercises | Q 6.23 | पृष्ठ ४५

संबंधित प्रश्न

A body is initially at rest. It undergoes one-dimensional motion with constant acceleration. The power delivered to it at time t is proportional to ______.


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  1. How much work does she do against the gravitational force?
  2. Fat supplies 3.8 x 107J of energy per kilogram which is converted to mechanical energy with a 20% efficiency rate. How much fat will the dieter use up?

A heavy stone is thrown from a cliff of height h with a speed v. The stoen will hit the ground with maximum speed if it is thrown 


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A heavy stone is thrown in from a cliff of height h in a given direction. The speed with which it hits the ground
(a) must depend on the speed of projection
(b) must be larger than the speed of projection
(c) must be independent of the speed of projection
(d) may be smaller than the speed of projection.


Figure shows a particle sliding on a frictionless track which terminates in a straight horizontal section. If the particle starts slipping from point A, how far away from the track will the particle hit the ground?


A block of mass m is attached to two unstretched springs of spring constants k1 and k2 as shown in the following figure. The block is displaced towards the right through a distance x and is released. Find the speed of the block as it passes through the mean position shown.


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A particle is released from height S from the surface of the Earth. At a certain height, its kinetic energy is three times its potential energy. The height from the surface of the earth and the speed of the particle at that instant are respectively ______.


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(g = 10 m/s2)

  


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